Nickel-nanoparticles-assisted direct copper-electroplating on polythiophene conductive polymers for PCB dielectric holes

Abstract

The pursuit for high throwing power (TP) in copper-hole metallization has been regarded as a major issue in the field of printed circuit boards (PCB). In this work, a membrane composed by polythiophene (PT) conductive polymers to replace electroless-plating copper layer is developed and investigated. High value of TP for dielectric holes on PCB is achieved by distributing nickel nanoparticles (NiNPs) on the PT membrane. During the electroplating process, NiNPs acting as seed clusters adsorb onto the surface of PT, effectively improve the copper electrocrystallization and thus increase the deposition rate of copper in the holes, enhancing TP of dielectric through-holes (THs) and filling rate of blind via. The results from morphological, electrical and thermal shock characterization validate that the copper layer formed by electroplating in the presence of NiNPs on the PT membrane has outstanding practical qualities.